Modern vehicles are typically equipped with several independent electronic systems. For instance, most modern vehicles have a sound system and a security system. Most late model vehicles are also constructed with a diagnostic system that analyzes performance of the vehicle's engine, transmission and fuel system, and other components (1996 or later for OBD II, 1993 or later for OBD I). In some recent models, vehicles are being equipped with a navigation system that incorporates a global positioning system (GPS) receiver to receive signals from a satellite network for computing coordinates that locate the vehicle over the surface of the earth with regard to longitude, latitude, and altitude. Cellular communications systems have also been added to vehicles. These communications systems enable the vehicle driver or occupant to transact telephone calls from their vehicle.
While these various electronics systems have proven useful to vehicle users, there is a drawback in that the systems are unrelated and incompatible. Each system employs separate proprietary dedicated processors or ASICs (application specific integrated circuits) which execute incompatible proprietary software. If a vehicle owner would like to add a security system to his/her vehicle, the owner must purchase an entire security system from one of the vendors and have it custom installed. There is no way to add security functionality to an existing electronics system, such as the navigation system or the sound system.
U.S. patent application Ser. No. 08/564,586 entitled “Vehicle Computer System,” which was filed on Nov. 29, 1995 in the names of Richard D. Beckert, Mark M. Moeller, and William Wong, describes a vehicle computer system that is capable of integrating these diverse and separate systems as well as offering a general purpose computing platform that allows for easy expandability. The vehicle computer system provides an open hardware architecture and supports an open platform operating system. The open platform operating system supports multiple different applications that can be supplied by a software vendor. For instance, the operating system can support applications pertaining to entertainment, navigation, communications, security, diagnostics, and others. In the preferred implementation, the operating system is a multitasking operating system capable of concurrently running multiple applications.
This invention is directed to the audio entertainment system implemented by the vehicle computer system.